[PSA] protein is not what most of this community thinks it is
protein is not what most of this community thinks it is. It comes up every few weeks and the answer has not changed.
How to make a DEXA comparison mean anything.
Same machine, same clinic, same protocol. Same hydration and fasting state, as far as you can manage. At least three to four months apart, because the measurement error is large relative to short-term change. Three scans rather than two, because the first pair cannot distinguish a trend from noise.
Do less than that and you have two numbers with an offset of unknown size, which people then react to by rebuilding a training programme. The free alternative — a few tracked lifts and a monthly waist measurement — is directionally informative, costs nothing, and is far harder to over-interpret.
DEXA has a meaningful coefficient of variation, and it differs between machines and protocols. Comparing scans from different clinics adds a systematic offset that is invisible on the report.
Some lean mass loss accompanies weight loss in any deficit. Resistance training and adequate protein intake are the two interventions with the best evidence for limiting the proportion.
Ask me anything specific. Anything general I will probably get wrong.
best — the order this archive was captured in
Fat-free mass index is a ratio of fat-free mass to height squared. It moves when either term does, which makes it awkward to interpret during active weight change.
Strength retention is an imperfect but free longitudinal proxy: it is affected by neural factors and by being in a deficit, so it tracks tissue change loosely rather than exactly.
Tracked grip strength and three lifts monthly. Cheaper than scanning and directionally the same answer.
Retitled — the original claimed a composition change the scans cannot distinguish.
Fasted and hydrated the same way for both scans?
This. Same machine, same protocol, or the DEXA comparison is measuring the scanner.
How many weeks between the two scans?
Have the lifts held, dropped, or moved around?
Careful, that is a nutrition prescription aimed at another member and this board does not do those.
a single DEXA is a number, two is a comparison, three is a trend
Not convinced by that DEXA comparison. Different machine, different protocol, and the difference is inside the error.
lean mass loss during weight loss is expected, the question is how much
Agreed — protein and resistance training. Everything else in these threads is a rounding error on those two.
Compared two scans from different clinics and panicked over a difference that was inside the error margin.
Right — strength retention is a free proxy and it tracks better than most people expect.
resistance training first, cardio if there is time left
- 1Tracked grip strength and three lifts monthly. Cheaper than scanning and…6 comments in this branch · started by u/rasmus_petrescu
- 2Have the lifts held, dropped, or moved around?6 comments in this branch · started by u/cold_chromatogram_only